here are some user who have them
I use those SCD's on cyclic and the GCD on the tail, off a 2s LiPo and they are phenomenal. plus the price is totally right. Try a gcd on your tail and I bet you will like it :thumbup:

fyi for frequency, Hyperion servos can be run up to 400mhz so on swash you can max it out, and on tail set to 333

center is 1520

and they support up to 400mhz
http://i452.photobucket.com/albums/qq250/RCnexgen/HypServoInfoHe1ista.jpg